Spending a lot of money to get poked with a needle may not be at the top of your pre-trip to-do list, but it should be. While some countries require proof of certain immunizations before they theoretically permit entry (details later in this post), there are a couple of vaccinations all travelers should get, barring any prohibitive allergies.

Getting vaccinated greatly reduces or virtually eliminates the odds of contracting certain serious illnesses or travel-related diseases, and helps prevent the spread of contagions. This is especially critical in developing countries, where there is generally little in the way of preventative or active health care, and lack of sanitation provides a fertile breeding ground for disease. As is true at home, infants, children, the elderly, and immuno-compromised are at greatest risk.

I consulted with Dr. John Szumowski, Clinical Fellow of the University of Washington Medical Center’s Division of Allergy and Infectious Disease, for expert advice before compiling the following list. As he pointed out, it’s tricky to generalize which immunizations are most important, since it depends upon where you’re going, and what you’re doing there.

That said, all of the immunizations on this list are a good idea if you travel frequently to developing nations, even if it’s for business or budget travel. They are especially important to have if you eat street food or visit rural areas.

The top five, after the jump.

[Photo credit: Flickr user johnnyalive]1. Flu
With flu epidemics making annual headlines, there’s no reason not to get a flu shot. This is especially true if you fly frequently or use other forms of public transit. Think of an airplane as a flying petri dish; why risk ruining your trip, or exposing others if you’re coming down with something? If you have an underlying health condition such as asthma, diabetes, or other lung or heart disease, it’s of particular importance to get immunized.

2. Tetanus
I grew up on a ranch, so tetanus shots have always been a part of my life. Many people don’t think about getting a tetanus vaccine, however, and as Dr. Szumowski points out, “It’s under-appreciated, and worth getting prior to travel given challenges of obtaining adequate, timely wound care.” Beats lockjaw, any day.

3. Hepatitis A
“Hepatitis A is common and can occasionally be quite serious,” cautions Dr. Szumowski. “For anyone with underlying liver disease (e.g. chronic hepatitis B or C) this is an especially important vaccination.”

4. Polio
Polio hasn’t been fully eradicated in parts of the developing world, so an inactivated poliovirus booster is important when traveling to areas where it’s still a problem, such as Nigeria and India.5. Typhoid
This vaccine can be taken either orally or by injection. Be aware that you must avoid mefloquine (an anti-malarial) or antibiotics within 24 hours of the vaccine doses.

Additional vaccines
Depending upon your destination, you may also require, by law, a Yellow Fever (tropical South America and sub-Saharan Africa), or Japanese Encephalitis/JE vaccination (parts of Asia and the Western Pacific). Dr. Szumowski recommends JE vaccine if you’re traveling for an extended (over one month) period in rural areas of affected countries.

Rabies vaccine isn’t usually recommended, but if you travel extensively in developing nations or have/expect frequent contact with animals, it’s a good idea. I’ve had a couple of canine-related experiences that have sold me on the idea. Dr. Szumowski notes that “excellent wound care and post-bite medical evaluation are still needed,” even if you’ve had a rabies pre-exposure vaccination.

Tips
It’s critical to allow ample time before your trip to allow the protective effects of the vaccines to establish themselves. Go to the Centers for Disease Control and Prevention’s vaccinations page for more information on what’s required and epidemic updates, if applicable. Often, your GP, internist, or local drugstore can provide some of these vaccinations; others require a specialist. For locations of a travel medicine clinic near you, click here.

Carry your immunization card with you as proof of vaccination, and email yourself a scanned copy, as well. The same goes for copies of your medical insurance cards.

Practice good hygiene and get enough rest, inasmuch as possible, while traveling, to maintain a healthy immune system. Airborne and Emergen-C are great immunoboosters to carry with you.

Consider travel insurance if you’ll be in a remote or sketchy area, or engaging in high-risk outdoor pursuits.